Over time in empty ground there grow plants: 1.lichens, 2.small bushes, 3.small trees, 4.pine trees and that area become forest.
Answer:
<em>The correct option is D. Theory</em>
Explanation:
The scientific method of research begins with a question.
To answer this question, a hypothesis is made. A hypothesis can be described as a tentative statement which is testable.
To test the validity of a hypothesis, observations and experiments are made. Based on the results from the observations and experiments, results are drawn and conclusions are made.
A scientific theory is a wide description for a hypothesis which is well tested again and again by observations and experiments. However, with time a scientific theory might change if new researchers are made.
Cross plants that have very different characteristics.
Valence Electrons are on the outer shell of a atom. The outer shell is also known as the valence shell so outer electrons or valence electrons are on the outer shell or valance shell.
The creation of DNA fragments with ends that can join with other DNA is achieved by the use of restrictive enzyme analysis.
<h3>What are restriction enzymes?</h3>
They are enzymes utilized in genetic engineering or gene recombination technology to cut DNA at some specific points in other to have sticky ends.
The sticky ends DNAs are able to join with other DNAs using these ends. Another enzyme (Ligase) is utilized to join the DNA back once the desired DNA has been inculcated.
More on restriction enzymes can be found here: brainly.com/question/13944056
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